The solenoid is a long cylindrical coil of wire consisting of a large no. of turns bound together very tightly.When current is flown through solenoid,One end of the Solenoid behaves like North Pole and the other end behaves like the South Pole. Magnetic field lines inside the solenoid are in the form of parallel straight lines.
This means that the field is same at all the points inside the solenoid.
Question 2) What kind of magnetic field is produced by a current carrying solenoid? Solution
The magnetic field due to a solenoid is very much similar to that of a bar magnet. The pattern of the magnetic field lines around a current-carrying solenoid is similar to that of bar magnet.Just like a bar magnet, one end of the solenoid behaves as a magnetic north pole, while the other behaves as the South Pole.
Question 3) Why does a compass needle show deflection when brought near a bar magnet? Solution
The needle of a compass is a small magnet. Thatís why when a compass needle is brought near a bar magnet, its magnetic field lines interact with that of the bar magnet. Hence, a compass needle gets deflected.
Question 4) Why are magnetic field lines more crowded towards the pole of a magnet? Solution
Strong force near the poles
Question 5) What are magnetic field lines? Question 6) Draw a diagram to represent a uniform magnetic field in a given region. Question 7) For same current flowing through a solenoid and a straight conductor, the magnetic field produced by a solenoid is much stronger than the magnetic field produced by a straight current carrying conductor. State one reason to justify this statement. Question 8) Why does a current carrying conductor experience a force when it is placed in a magnetic field? Solution
The current carrying conductor generates it own magnetic field around it. This interracts with the external magnetic field. When two magnetic fields interact there will be attraction and repulsion between them based on the direction of the external magnetic field and the direction of the current in the conductor. That is reason the current caryying conductor experiences a force.
Question 9) Whenever there is a relative motion between magnet and a coil, a current is induced in the coil. Name this phenomenon. Solution
Question 10) How is the type of current that we receive in domestic circuit different from the one that runs in a clock? Solution
We receive Alternating current in Domestic circuit while direct currents runs in a clock
Question 11) What type of current is given direct current? Question 12) What type of current is used in household supply? Solution
Question 13) Why do we connect earth wire in a house? Give two reasons. Question 14) What is the difference between a direct current and an alternating current. How many times does AC used in India change direction in one second? Question 15) What is the role of fuse used in series with any electrical appliance? Why should a fuse with defined rating not be replaced by one with a larger rating? Question 16) A magnetic compass shows a deflection when placed near a current – carrying wire. How will the deflection of the compass get affected if the current in the wire is increased? Support your answer with a reason. Question 17) What is the full form of MRI? Solution
Magnetic Resonance Imaging
Question 18) Why can’t two magnetic field lines cross (intersect) each other? Solution
Magnetic Field lines cannot cross each other. If it happens that at point of intersection, the compass needle will point in two direction which is not possible
Question 19) Compare the pattern of the magnetic field around a solenoid with the magnetic field around a bar magnet.
Question 20) A compass needle is placed near a current – carrying wire. State your observation for the following cases and give reason for the same in each case:
(i) Magnitude of electric current in the wires increased.
(ii) The compass needle is displaced away from the wire. Question 21) State the rule for finding the direction of the magnetic field produced around a current carrying conductor. Solution
Flemings Left Hand rule
Question 22) Mention the shape of the magnetic field lines around a current carrying straight conductor. Solution
Question 23) A current carrying conductor in a magnetic field experiences a force. Write the condition for this force to be maximum. Solution
Force is maximum when current direction is perpendicular to Magnetic field direction
Question 24) Name and state the rule that helps to find the induced current in electromagnetic Induction. Solution
Flemings Right hand rule
Question 25) An alternating electric current has a frequency of 50 Hz. How many times does it changes its direction in one second? Give reason for your answer. Solution
50Hz means 50 cycle/sec. Now in one cycle, current changes direction twice, So 100 times per sec
Question 26) Explain why electrical appliances are connected in parallel in household circuits. Question 27) Draw the pattern of magnetic field lines of a solenoid through which a steady current flows. Question 28) A coil of insulated wire is connected to a galvanometer. What would beseen if a bar magnet with its south pole towards one face of the coil is:
(a) Moved quickly towards it?
(b) Moved quickly away from it?
(c) Placed near its once face?
(d) Name the phenomena involved. Solution
a) Deflection in galvanometer
b) Deflection in galvanometer
c) No deflection in galvanometer
d) Electromagnetic Induction
Question 29) What is the role of fuse, used in series with any electrical appliance? Why should a fuse with defined rating not be replaced by one with a larger rating? Question 30) Two circular coils A and B are placed close to each other. If the current in the coil A is changed, will some current be induced in coil B? Give reason.